Final answer:
The question seeks to understand the probability related to call center activity and customer usage in excess of contract allowances, which depends on the probability distributions involved. Particularly, for cell phone contract excess usage, an exponential distribution model with a mean of 22 minutes is mentioned.
Step-by-step explanation:
The question pertains to determining the probability that call center employees will make more than 20 long-distance phone calls during peak hours, given that the average is 20 calls. Furthermore, the probability of the mean excess time used being over 20 minutes among a sample of 80 customers who exceed their cell phone contract time allowance is provided as 0.7919. Additionally, a law office switchboard on average receives 5.5 incoming calls, with the existing staff able to handle up to six calls, during the peak noon hour on Mondays.
To answer the initial question: The probability that call center employees make more than the minimum average of 20 long-distance calls during the peak time is not directly provided but could be inferred or calculated given a specific distribution model. However, for example 7.9, which addresses the excess time used by customers exceeding their basic cell phone contract's allowable time, we understand that this time follows an exponential distribution with a mean of 22 minutes. Probability calculations would require knowledge of the distribution parameters.